There is known a funnel which comprises a downwardly tapered frustoconical shell having at its lower end a narrow outlet and at its upper end a wide mouth. A tube is provided at the axis of this frustoconical shell and extends substantially through it such that its lower end projects beyond the outlet and its upper end above the mouth. This tube is slidable limitedly within the shell and is supported adjacent its upper end by a spider or the like. A handle is provided on the upper end of the tube and an upwardly tapered frustoconical valve body on the lower end so that when the handle is lifted the valve body blocks the outlet of the funnel, whereas when the handle is lowered fluid within the shell may flow out from the outlet thereof. During such filling operation air trapped within a vessel over which the shell is engaged may exit upwardly through the hollow tube.
It is known to provide a spring between the handle and the sleeve guiding and journaling the tube so as to urge the valve body into engagement with the outlet under normal conditions. The handle is formed with a bore in line with the central passage of the tube so that air bleeding out of the vessel being filled comes straight up.
A substantial disadvantage with such a structure is that a certain amount of liquid is entrained by the upwardly rising stream of air and is projected from the upper end of the tube. This problem is particularly bothersome when one is filling a vessel having a relatively narrow neck. A contributing factor to this problem is that the liquid that pours into the vessel forms a tubular screen around the valve body so that the air flowing upwardly through this body must inherently pass through this screen and therefore entrains a certain amount of liquid. When the liquid is an acid or other potentially dangerous substance this situation can constitute a relatively grave danger.